Alphabet is tumbling after a fourth quarter whiff and names John Hennessy as new board chair

Google parent company Alphabet’s big run over the past few months came to a screeching halt today after it came out with its fourth-quarter results, which fell beneath expectations set by Wall Street for the advertising giant — sending the stock down around 5 percent and shaving off billions in market cap.

While Google owns a massive chunk of the advertising system — and it still continues to print money — it’s found itself trying to diversify itself away from that with a series of other big bets on products like hardware and cloud computing. That’s starting to pay off as growth in its “other revenues” and “other bets” continues to rise year-over-year, but there are still a couple of signs that point to a potentially rocky future for Google.

Like other big tech companies reporting this quarter, Google logged a $9.9 billion charge related to changes in U.S. tax law. Here’s the scorecard:

In particular, Google’s last quarters have been marked with the creeping shadow of increasing costs for its traffic acquisition as a percentage of Google’s revenue, or TAC. While for the past several quarters it hasn’t raised any massive alarm bells, it could represent a potential problem for Google in the future as more and more activity shifts to mobile devices. It’s something that’s come up a couple of times from analysts poking around at the subject on quarterly calls to discuss the earnings results, and it is still continuing to creep up.

Today is a surprising slip-up for Google, which, while it continues to print money and beat Wall Street’s expectations on the revenue front, found itself tumbling after its fourth-quarter earnings came out. In the past year, Google’s stock has risen nearly 50 percent: